This week as part of our continuing study of the human body we are learning about the parts of our blood. I did a little demonstration at group time to illustrate this and also showed the children microscope images of the various parts. Below you can see the little basket I put together for my demonstration. It contains a jar of yellow water, a jar with cheerios, a jar with small white marshmallows, a shaker of salt, a bottle of red food coloring, a spoon, and a few purple porcupine balls.
First I asked the children what color their blood is when it comes out of a cut or scrape. Then I told them that even though blood LOOKS red, the liquid part of it is actually yellow and is called plasma. I then showed them the jar of yellow water as pictured below.
Next I explained that the blood contains salt and other chemicals and shook a little salt from the shaker into the yellow plasma. Then I told them that there are other things floating in the blood that are very important for our bodies. First, there are billions of red blood cells that look a little like donuts without a hole. Their job is to carry oxygen. There are so many of them floating in the plasma that it makes the blood look red. At this point I dumped in the Cheerios to represent the red blood cells and squirted in some red food coloring. Next, there are white blood cells. Their job is to fight germs and disease. I added the marshmallows to represent the white blood cells. And finally, there are platelets whose job is to help stop bleeding when we get injured. I used the purple porcupine balls for the platelets because in our microscopic photo of the platelets, they somewhat resemble spiny balls that are purplish. Below you can see our finished "blood."
As one of my afternoon students was leaving today, he showed me a small scab on his knee and told me that blood had come out. And he said, "Then those purple things came over and stopped my blood from coming out." I was pretty impressed that he had already applied this new knowledge from our group lesson. Young children's brains are truly amazing..............a fact that was embraced deeply by Maria Montessori. Isn't learning fun??